Understanding the Q Factor in Parallel Resonant Circuits

AI Thread Summary
The discussion clarifies the Q factor in parallel resonant circuits, noting that while the Q factor of the inductor and the entire parallel LC tank circuit are closely related, they are not identical. The formula Q = wL/R applies to the inductor, where R is the inductor's series resistance, but the overall Q factor for the tank circuit can differ based on component quality. High-quality capacitors minimize losses, making the inductor's resistance more significant in determining the circuit's Q factor. The conversion of the inductor's series resistance to parallel resistance using Rp = R/Q^2 simplifies analysis in circuit design. Understanding these relationships is crucial for accurate circuit performance evaluation.
appoos
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hi there..in some places, i saw the usage "the Q factor of parallel LC tank ckt" while in some others, the Q factor of the inductor used in tank ckt is given..are they same??
As far as i know,Q=wL/R is the thing for inductor ,where R is inductor's series resistance..is the formula same for the entire parallel tank ckt??

Also, i would like to know why, during analysis, do we convert series R of inductor to parallel resistance by formula, Rp =R/Q^2 ??
 
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appoos said:
hi there..in some places, i saw the usage "the Q factor of parallel LC tank ckt" while in some others, the Q factor of the inductor used in tank ckt is given..are they same??
Close to being the same. Low-loss capacitors are easy to find, so most of the losses are in the coil.
As far as i know,Q=wL/R is the thing for inductor ,where R is inductor's series resistance..is the formula same for the entire parallel tank ckt??
Practically, provided you use high quality capacitors. But that's not DC resistance.
Also, i would like to know why, during analysis, do we convert series R of inductor to parallel resistance by formula, Rp =R/Q^2 ??
It probably makes analysis easier.

Welcome to PF.
 
thank you..
 

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